WO2023234194A1

WO2023234194A1 - Light source unit, video display device, and automobile

Info

Publication number: WO2023234194A1
Application number: PCT/JP2023/019643
Authority: WO
Inventors: 和北原; 貴紀有賀; 肇秋元
Original assignee: 日亜化学工業株式会社
Priority date: 2022-05-30
Filing date: 2023-05-26
Publication date: 2023-12-07

Abstract

A light source unit according to the present invention comprises: a display device that has a plurality of pixels and can display an image; a color-changing sheet on which light emitted from the display device is incident; an image-forming optical system; and a driving unit that changes the positional relationship between the display device and the color-changing sheet. The image-forming optical system forms a first image corresponding to the aforementioned image. The color-changing sheet comprises: a first region on which light from the image is incident and which emits light of a first color; and a second region on which light from the image is incident and which emits light of a second color. The driving unit changes the positional relationship between the display device and the color-changing sheet between a first positional relationship, in which light emitted from one of the pixels is incident on the first region, and a second positional relationship, in which light emitted from the one pixel is incident on the second region.

Description

Light source units, video display devices and automobiles

Embodiments relate to a light source unit, a video display device, and an automobile.

Patent Document 1 discloses that light emitted from a display device capable of displaying an image is sequentially reflected by a plurality of mirrors, and the light reflected by the last mirror is further directed toward the user by a reflective member such as a windshield. A technique is disclosed in which a virtual image is reflected and allows a user to view a virtual image corresponding to an image displayed by a display device. However, when attempting to colorize an image using the technique disclosed in Patent Document 1, pixels corresponding to each color are required, resulting in a problem that the display device becomes larger.

International Publication No. 2016/208195

An object of the embodiments of the present invention is to provide a light source unit, a video display device, and an automobile that are small and capable of displaying color images.

A light source unit according to an embodiment of the present invention includes a display device having a plurality of pixels and capable of displaying an image, a color changing sheet into which light emitted from the display device is incident, an imaging optical system, and the display device. and a drive unit that changes the positional relationship of the color change sheet. The imaging optical system includes an input element into which the light emitted from the color change sheet enters, and an output element into which the light that passes through the input element enters, and the light emitted from the output element forms the image. forming a corresponding first image; The color change sheet includes a first area into which light is incident from the pixel and emits light of a first color, and a first area into which light is incident from the pixel and which emits light of a second color different from the first color. and a second area that emits the radiation. The drive unit sets the positional relationship between the display device and the color change sheet to a first positional relationship in which light emitted from one of the pixels enters the first area, and a first positional relationship in which light emitted from one of the pixels enters the first area. and a second positional relationship in which the light enters the second region. The imaging optical system has substantially telecentricity on the first image side. The light emitted from the display device has a substantially Lambertian light distribution.

An image display device according to an embodiment of the present invention includes the light source unit and a reflection unit that is spaced apart from the light source unit and reflects light emitted from the imaging optical system. The first image is formed between the light source unit and the reflection unit.

According to the embodiment, it is possible to realize a light source unit, a video display device, and a car that are small and capable of displaying color images.

FIG. 1 is an end view showing a video display device according to a first embodiment. FIG. 2A is a plan view showing the display device of the light source unit according to the first embodiment. FIG. 2B is a plan view showing the color changing sheet of the light source unit according to the first embodiment. FIG. 2C is an end view showing the display device, color change sheet, and drive unit of the light source unit according to the first embodiment. FIG. 3 is an end view showing the display device of the video display device according to the first embodiment. FIG. 4 is an end view showing a change in the positional relationship between the pixels of the display device and the area of the color change sheet. FIG. 5A is a plan view showing a change in the positional relationship between the pixels of the display device and the area of the color change sheet in the first embodiment. FIG. 5B is a plan view showing a change in the positional relationship between the pixels of the display device and the area of the color change sheet in the first embodiment. FIG. 5C is a plan view showing a change in the positional relationship between the pixels of the display device and the area of the color change sheet in the first embodiment. FIG. 6 is a schematic diagram showing the scenery seen from a viewer in the driver's seat in the first embodiment. FIG. 7A is a schematic diagram showing the principle of the light source unit according to the first embodiment. FIG. 7B is a schematic diagram showing the principle of a light source unit according to a reference example. FIG. 8A is a graph showing a light distribution pattern of light emitted from one light emitting area in Examples 1, 11 and Reference Example. FIG. 8B is a graph showing the uniformity of brightness of the second image in Examples 1 to 12 and the reference example. FIG. 9A is a plan view showing a color change sheet of a light source unit according to a first modification of the first embodiment. FIG. 9B is a plan view showing a change in the positional relationship between the pixels of the display device and the area of the color change sheet in the first modification of the first embodiment. FIG. 9C is a plan view showing a change in the positional relationship between the pixels of the display device and the area of the color change sheet in the first modification of the first embodiment. FIG. 10 is a plan view showing a color change sheet of a light source unit according to a second modification of the first embodiment. FIG. 11 is an end view showing a display device of a video display device according to the second embodiment. FIG. 12 is a plan view showing a color changing sheet of a light source unit according to the second embodiment. FIG. 13 is a plan view showing a color changing sheet of a light source unit according to a first modification of the second embodiment. FIG. 14 is a plan view showing a color changing sheet of a light source unit according to a second modification of the second embodiment. FIG. 15 is a plan view showing a color changing sheet of a light source unit according to the third embodiment. FIG. 16 is a plan view showing a color change sheet of a light source unit according to a modification of the third embodiment. FIG. 17 is a diagram showing the relationship between the color of light emitted from the pixels of the display device and the color change sheet. FIG. 18 is a plan view showing a color changing sheet of a light source unit according to the fourth embodiment. FIG. 19 is a plan view showing a color changing sheet of a light source unit according to the fifth embodiment. FIG. 20 is a plan view showing a color changing sheet of a light source unit according to the sixth embodiment. FIG. 21 is an end view showing a video display device according to the seventh embodiment. FIG. 22 is a schematic diagram showing the scenery seen from a viewer in the driver's seat in the seventh embodiment. FIG. 23 is an end view showing a video display device according to the eighth embodiment. FIG. 24 is an enlarged cross-sectional view of a part of the display device and reflective polarizing element shown in FIG. 23. FIG. 25 is a side view showing a light source unit according to the ninth embodiment. FIG. 26 is a side view showing a light source unit according to a modification of the ninth embodiment.

Each embodiment and its modification examples will be described below with reference to the drawings. Note that the drawings are schematic or conceptual, and are emphasized or simplified as appropriate. For example, the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be shown differently depending on the drawing. Furthermore, in this specification and each figure, the same elements as those described in relation to the previous figures are given the same reference numerals, and detailed explanations are omitted as appropriate.

<First embodiment>
First, a first embodiment will be described.
FIG. 1 is an end view showing a video display device according to this embodiment.
FIG. 2A is a plan view showing the display device of the light source unit according to this embodiment.
FIG. 2B is a plan view showing the color change sheet of the light source unit according to this embodiment.
FIG. 2C is an end view showing the display device, color change sheet, and drive unit of the light source unit according to this embodiment.

As shown in FIG. 1, the video display device 10 according to the present embodiment includes a light source unit 11 and a reflection unit 12. The light source unit 11 includes a display device 110, an imaging optical system 120, a color change sheet 130, and a drive unit 140. The display device 110 has a plurality of pixels and can display images. Light emitted from the display device 110 enters the color change sheet 130 . The imaging optical system 120 receives the light emitted from the color change sheet 130 and forms a first image IM1 corresponding to the image displayed by the display device 110. The first image IM1 is a real image and an intermediate image. The drive unit 140 changes the positional relationship between the display device 110 and the color change sheet 130. The reflection unit 12 is spaced apart from the light source unit 11 and reflects the light emitted from the imaging optical system 120.

The video display device 10 is mounted on, for example, a car 1000 and constitutes a HUD (Head Up Display). The automobile 1000 includes a vehicle 13 and a video display device 10 fixed to the vehicle 13. The viewer 14 is a passenger of the automobile 1000, for example, a driver.

The display device 110 of the light source unit 11 displays an image that is desired to be viewed by the viewer 14 using the HUD. The color change sheet 130 changes the color of the image displayed by the display device 110 for each pixel. This mechanism will be described later. The imaging optical system 120 outputs the light emitted from the color change sheet 130 to the reflection unit 12, and forms a first image IM1 between the light source unit 11 and the reflection unit 12. The reflection unit 12 reflects the light emitted from the light source unit 11 toward the front windshield 13a of the vehicle 13. The front windshield 13a includes, for example, glass.

The front windshield 13a reflects the light arriving from the reflection unit 12 on its inner surface and makes it enter the eyebox 14a of the viewer 14. Thereby, the viewer 14 can visually recognize the second image IM2 corresponding to the image displayed by the display device 110 on the other side of the front windshield 13a. The second image IM2 is a virtual image larger than the first image IM1. The "eye box" refers to the area in front of the viewer's eyes where a virtual image can be viewed.

Hereinafter, in order to make the explanation easier to understand, the arrangement and configuration of each part will be explained using an XYZ orthogonal coordinate system. In this embodiment, the longitudinal direction of the vehicle 13 is referred to as the "X direction," the left-right direction of the vehicle 13 is referred to as the "Y direction," and the vertical direction of the vehicle 13 is referred to as the "Z direction." The XY plane is a horizontal plane of the vehicle 13. Of the X directions, the direction of the arrow (forward) is called the "+X direction", and the opposite direction (backward) is also called the "-X direction". Further, in the Y direction, the direction of the arrow (to the left) is referred to as the "+Y direction", and the opposite direction (to the right) is also referred to as the "-Y direction". Further, in the Z direction, the direction of the arrow (upward) is referred to as the "+Z direction", and the opposite direction (downward) is also referred to as the "-Z direction".

Furthermore, in FIG. 1, the position where the first image IM1 is formed is indicated by a circular mark. Similar to the first image IM1, the position where the second image IM2 is formed is indicated by a circular mark. On the other hand, in the display device 110, the positions from which the principal ray L that reaches each mark of the first image IM1 is emitted are indicated by square marks. In this way, in order to make the explanation easier to understand, the emission position of each principal ray L on the display device 110 is set to a different mark from the imaging position of the first image IM1 and the imaging position of the second image IM2. As shown in , the image displayed on the display device 110, the first image IM1, and the second image IM2 have a generally similar relationship.

As shown in FIG. 2A, in the display device 110, a plurality of pixels 110p are arranged in a matrix along the first direction and the second direction. The second direction intersects, for example is perpendicular to, the first direction. For example, the first direction is the horizontal direction of the image, and the second direction is the vertical direction of the image. In this embodiment, the first direction is the X direction, and the second direction is the Y direction. The color of the light emitted from each pixel 110p is the same, and in this embodiment, it is white. The light emitted from the display device 110 has a substantially Lambertian light distribution. The specific configuration of the display device 110 and the Lambertian light distribution will be described in detail later.

As shown in FIG. 2B, the color change sheet 130 has a plurality of regions 130p arranged in a matrix along the first direction and the second direction. The shape and size of each region 130p are approximately equal to the shape and size of each pixel 110p of the display device 110, and the arrangement period of the regions 130p in the first direction and the second direction is approximately equal to the arrangement period of the pixels 110p. Therefore, the pixels 110p of the display device 110 and the regions 130p of the color change sheet 130 have a one-to-one correspondence, and all or most of the light emitted from one pixel 110p enters one region 130p. However, as described later, the combination of the pixel 110p and the region 130p changes depending on the operation of the drive unit 140.

There are three types of regions 130p: a first region 130a, a second region 130b, and a third region 130c. The first region 130a receives light from the pixel 110p of the display device 110 and emits light of the first color. The second region 130b receives light from the pixel 110p and emits light of a second color different from the first color. The third region 130c receives light from the pixel 110p and emits light of a third color different from the first color and the second color.

In this embodiment, the first region 130a, the second region 130b, and the third region 130c are repeatedly arranged along the first direction (X direction) and the second direction (Y direction). Therefore, when focusing on a specific area of the color change sheet 130, the first area 130a and the second area 130b are arranged along the first direction (X direction), and the first area 130a and the third area 130c are arranged along the first direction (X direction). They are arranged along the second direction (Y direction). Note that although 100 regions 130p are shown in 10 rows and 10 columns in FIG. 2B, the present invention is not limited to this, and for example, about several thousand regions 130p may be provided.

In this embodiment, the first region 130a is made of a blue film, and the first color is blue. The second region 130b is made of a green film, and the second color is green. The third region 130c is made of a red film, and the third color is red. That is, white light enters the first region 130a from the pixel 110p of the display device 110, and blue light is emitted. White light enters the second region 130b from the pixel 110p, and green light is emitted. White light enters the third region 130c from the pixel 110p, and red light is emitted. In FIG. 2B, the first region 130a that emits blue light is labeled with the letter "B," the second region 130b that emits green light is labeled with the letter "G," and the second region 130b that emits red light is labeled with the letter "G." The letter "R" is attached to the third region 130c. The same applies to other embodiments and modifications described later.

As shown in FIG. 2C, the color change sheet 130 is arranged on the light emission side of the display device 110, that is, on the −Z direction side. The drive unit 140 includes, for example, an actuator, and changes the positional relationship between the display device 110 and the color change sheet 130 by moving the color change sheet 130. Note that the drive unit 140 may move the display device 110 or may move both the display device 110 and the color change sheet 130. In the following description, an example in which the drive unit 140 moves the color change sheet 130 will be described.

Next, the configuration of the video display device 10 other than the above will be explained.
First, the display device 110 will be explained.
FIG. 3 is an end view showing the display device of the video display device according to this embodiment.

The display device 110 of the light source unit 11 is an LED display. In the display device 110, a plurality of LED elements 112 are arranged in a matrix. One or more LED elements 112 are arranged in each pixel 110p of the display device 110.

As shown in FIG. 3, in the display device 110, each LED element 112 is mounted face-down on the substrate 111. However, each LED element may be mounted face-up on the board. Each LED element 112 has a semiconductor stack 112a, an anode electrode 112b, and a cathode electrode 112c.

The semiconductor stack 112a includes a p-type semiconductor layer 112p1, an active layer 112p2 placed on the p-type semiconductor layer 112p1, and an n-type semiconductor layer 112p3 placed on the active layer 112p2. For example, a gallium nitride-based compound semiconductor represented by In _X Al _Y Ga _1-XY N (0≦X, 0≦Y, X+Y<1) is used for the semiconductor stack 112a. The light emitted by the LED element 112 is visible light in this embodiment.

The anode electrode 112b is electrically connected to the p-type semiconductor layer 112p1. Further, the anode electrode 112b is electrically connected to the wiring 118b. The cathode electrode 112c is electrically connected to the n-type semiconductor layer 112p3. Further, the cathode electrode 112c is electrically connected to another wiring 118a. For example, a metal material can be used for each

electrode

112b, 112c.

In this embodiment, a wavelength conversion member 115 is provided on each LED element 112. The light emitted from the LED element 112 enters the wavelength conversion member 115 . For example, the wavelength conversion member 115 faces the light exit surface 112s of the LED element 112. In this specification, the term "light exit surface of the LED element" refers to the surface of the LED element from which the light incident on the imaging optical system 120 mainly exits. In this embodiment, the surface of the n-type semiconductor layer 112p3 located on the opposite side of the surface facing the active layer 112p2 corresponds to the light exit surface 112s.

The wavelength conversion member 115 contains phosphor. In this embodiment, the LED element 112 emits blue light. The wavelength conversion member 115 contains a phosphor that absorbs blue light and emits green light, and a phosphor that absorbs blue light and emits red light. As a result, the wavelength conversion member 115 emits white mixed color light consisting of blue light, green light, and red light.

Hereinafter, the optical axis of light emitted from each pixel 110p will be simply referred to as "optical axis C." For example, the optical axis C is parallel to the XY plane on which the plurality of pixels 110p are arranged, and the light from one pixel 110p is irradiated on the first plane P1 located on the light emission side of the display device 110. Among the range where the brightness is maximum, the brightness is at the point a1 in the range where the light from this pixel 110p is irradiated on the second plane P2 which is parallel to the XY plane and is separated from the first plane P1. This is a straight line connecting the maximum point a2. If there are multiple points where the brightness is maximum, for example, the center point of those points may be set as the point where the brightness is maximum. Note that from a productivity standpoint, it is desirable that the optical axis C be parallel to the Z axis.

As described above, since the wavelength conversion member 115 is provided on the light emitting surface 112s of each LED element 112, the light emitted from the wavelength conversion member 115, that is, the light emitted from each pixel 110p, is as indicated by the broken line in FIG. As shown, it has a substantially Lambertian light distribution. Here, "the light emitted from each pixel has a substantially Lambertian light distribution" means that the luminous intensity in the direction of the angle θ with respect to the optical axis C of each pixel is on the optical axis C, where n is a value larger than 0. This means that the light distribution pattern can be approximated by cos ⁿ θ times the luminous intensity of . Here, n is preferably 11 or less, and even more preferably 1. Although there are many planes including the optical axis C of the light emitted from one pixel 110p, the light distribution pattern of the light emitted from this pixel 110p in each plane is approximately Lambertian light distribution, and The numerical values of n are also approximately equal.

Next, the imaging optical system 120 will be explained in detail.
As shown in FIG. 1, the imaging optical system 120 of the light source unit 11 is an optical system that includes all optical elements necessary to form the first image IM1 at a predetermined position. In this embodiment, an input element 121 into which light emitted from the display device 110 enters, an intermediate element 122 into which light reflected by the input element 121 enters, and an output element 123 into which light reflected by the intermediate element 122 enters. and has. The light emitted from the output element 123 forms a first image IM1. Note that the light that has passed through the input element 121 may enter the output element 123, and the intermediate element 122 may not be provided.

The imaging optical system 120 has approximately telecentricity on the first image IM1 side. Here, "the imaging optical system 120 has substantially telecentricity on the first image IM1 side" means that, as shown in FIG. This means that the plurality of chief rays L that reach the first image IM1 via the above are substantially parallel to each other before and after the first image IM1. The different positions are, for example, different pixels 110p of the display device 110. "The plurality of principal rays L are substantially parallel" means that they are substantially parallel within a practical range that allows for errors due to manufacturing precision, assembly precision, etc. of the components of the light source unit 11. When "the plurality of principal rays L are substantially parallel to each other", for example, the angle between the principal rays L is 10 degrees or less.

When the imaging optical system 120 has substantially telecentricity on the first image IM1 side, the plurality of principal rays L intersect with each other before entering the input element 121. Hereinafter, the point where the plurality of principal rays L intersect with each other will be referred to as a "focal point F." Therefore, whether or not the imaging optical system 120 has substantially telecentricity on the first image IM1 side can be confirmed by the following method using, for example, the retrograde property of light. First, a light source capable of emitting parallel light, such as a laser light source, is placed near the position where the first image IM1 is formed. The output element 123 of the imaging optical system 120 is irradiated with light emitted from this light source. Light emitted from this light source and passed through the output element 123 enters the input element 121. If there is a point where the light emitted from the input element 121 is focused before reaching the display device 110, that is, a focal point F, the imaging optical system 120 has approximately telecentricity on the first image IM1 side. It can be determined that there is.

Since the imaging optical system 120 has substantially telecentricity on the first image IM1 side, the imaging optical system 120 includes light that passes through the focal point F and its vicinity, out of the light emitted from each pixel of the display device 110. is mainly incident. Each optical element constituting the imaging optical system 120 will be described below.

The input element 121 is located on the −Z side of the display device 110 and is arranged to face the display device 110. The input element 121 is a mirror having a concave mirror surface 121a. The input element 121 reflects the light emitted from the display device 110.

The intermediate element 122 is located on the -X side of the display device 110 and the input element 121, and is arranged to face the input element 121. The intermediate element 122 is a mirror having a concave mirror surface 122a. Intermediate element 122 further reflects the light reflected by input element 121.

The input element 121 and the intermediate element 122 constitute a bending portion 120a that bends the plurality of principal rays L so that the plurality of principal rays L emitted from different positions of the display device 110 are substantially parallel to each other. The mirror surfaces 121a and 122a are biconic surfaces in this embodiment. However, the mirror surface may be a part of a spherical surface or may be a free-form surface.

The output element 123 is located on the +X side of the display device 110 and the input element 121, and is arranged to face the intermediate element 122. The output element 123 is a mirror having a flat mirror surface 123a. The output element 123 reflects the light that has passed through the input element 121 and the intermediate element 122 toward the formation position of the first image IM1. Specifically, a plurality of principal rays L that are substantially parallel due to the bending portion 120a are incident on the output element 123. The mirror surface 123a is inclined with respect to the XY plane, which is the horizontal plane of the vehicle 13, so that the more it goes in the -Z direction, the more it goes in the +X direction. Thereby, the output element 123 reflects the light reflected by the intermediate element 122 in a direction inclined with respect to the Z direction such that the more it goes in the -Z direction, the more it goes in the +X direction. As shown in FIG. 1, the output element 123 directs the plurality of principal rays L so that the plurality of principal rays L, which have become substantially parallel due to the bending portion 120a, head toward the formation position P of the first image IM1. A direction changing unit 120b for changing the direction is configured.

In this embodiment, the optical path between the input element 121 and the intermediate element 122 extends in a direction intersecting the XY plane. Further, the optical path between the intermediate element 122 and the output element 123 extends in a direction along the XY plane. Since a part of the optical path within the imaging optical system 120 extends in a direction intersecting the XY plane, the light source unit 11 can be downsized to some extent in the direction along the XY plane. Furthermore, since the other part of the optical path within the imaging optical system 120 extends in the direction along the XY plane, the light source unit 11 can be downsized to some extent in the Z direction.

Furthermore, the optical path between the display device 110 and the input element 121 intersects with the optical path between the intermediate element 122 and the output element 123. In this way, by making the optical paths intersect with each other within the light source unit 11, the light source unit 11 can be made smaller.

However, the optical path within the light source unit is not limited to the above. For example, all optical paths within the imaging optical system may extend in a direction along the XY plane, or may extend in a direction intersecting the XY plane. Further, the optical paths within the light source unit do not need to intersect with each other.

The input element 121, the intermediate element 122, and the output element 123 each include a main body member made of glass or a resin material, and a metal film or dielectric material provided on the surface of the main body member and forming

mirror surfaces

121a, 122a, and 123a. It may also be configured with a reflective film such as a multilayer film. Further, the input element 121, the intermediate element 122, and the output element 123 may each be entirely made of a metal material.

As shown in FIG. 1, in this embodiment, the light source unit 11 is provided on the ceiling portion 13b of the vehicle 13. The light source unit 11 is arranged, for example, inside a wall 13s1 exposed inside the vehicle at the ceiling portion 13b. The wall 13s1 is provided with a through hole 13h1 through which light emitted from the output element 123 of the light source unit 11 can pass. The light emitted from the output element 123 passes through the through hole 13h1 and is irradiated into the space between the viewer 14 and the front windshield 13a. However, the light source unit may be attached to the ceiling surface. The through hole 13h1 may be provided with a transparent or translucent cover having a small haze value. The haze value is preferably 50% or less, and even more preferably 20% or less.

Although the imaging optical system 120 has been described above, the configuration and position of the coupling optical system are not limited to the above as long as it has substantially telecentricity on the first image side. For example, the number of optical elements constituting the direction changing section may be two or more.

Next, the reflection unit 12 will be explained.
As shown in FIG. 1, in this embodiment, the reflection unit 12 includes a mirror 131 having a concave mirror surface 131a. Mirror 131 is arranged to face front windshield 13a. The mirror 131 reflects the light emitted from the output element 123 and irradiates it onto the front windshield 13a. The mirror 131 may include a main body member made of glass, a resin material, or the like, and a reflective film such as a metal film or a dielectric multilayer film provided on the surface of the main body member and forming the mirror surface 131a. Further, the mirror 131 may be entirely made of a metal material. In one example, mirror surface 131a is a biconic surface. However, the mirror surface may be a part of a spherical surface or may be a free-form surface.

The light irradiated onto the front windshield 13a is reflected on the inner surface of the front windshield 13a and enters the eye box 14a of the viewer 14. Thereby, the viewer 14 visually recognizes the second image IM2 corresponding to the image displayed on the display device 110 on the other side of the front windshield 13a.

In this embodiment, the reflection unit 12 is provided on the dashboard portion 13c of the vehicle 13. The reflection unit 12 is arranged, for example, inside a wall 13s2 of the dashboard portion 13c of the vehicle 13 that is exposed inside the vehicle. The wall 13s2 is provided with a through hole 13h2 through which light emitted from the output element 123 of the light source unit 11 can pass. The light emitted from the output element 123 passes through the through hole 13h1 to form a first image IM1, and then passes through the through hole 13h2 and is irradiated onto the reflection unit 12. However, the reflection unit may be attached to the upper surface of the dashboard part. Alternatively, the reflection unit may be placed on the ceiling and the light source unit may be placed on the dashboard.

The path of light from the inner surface of the front windshield 13a toward the eyebox 14a is generally horizontal, completely horizontal, or slightly inclined so that the eyebox 14a side is higher. That is, this path is approximately parallel to the XY plane. In this embodiment, the light source unit 11 is placed above (+Z direction) and the reflection unit 12 is placed below (-Z direction) with respect to the XY plane including the path of this light. That is, the light source unit 11 and the reflection unit 12 are separated from each other with the XY plane interposed therebetween.

Although the reflection unit 12 has been described above, the configuration and position of the reflection unit are not limited to the above. For example, the number of optical elements such as mirrors constituting the reflection unit may be two or more. Note that the reflection unit 12 needs to be arranged so that, for example, sunlight irradiated from outside the vehicle through the front windshield 13a is not reflected toward the eye box 14a.

Next, the operation of the video display device 10 according to this embodiment will be explained.
FIG. 4 is an end view showing a change in the positional relationship between the pixels of the display device and the area of the color change sheet.
5A to 5C are plan views showing changes in the positional relationship between the pixels of the display device and the area of the color change sheet in this embodiment.
FIG. 6 is a schematic diagram showing the scenery seen from the viewer in the driver's seat in this embodiment.

As shown in FIG. 4, the drive unit 140 controls the positional relationship between the display device 110 and the color change sheet 130 such that light emitted from one pixel 110p of the display device 110 enters the first region 130a of the color change sheet 130. A first positional relationship, a second positional relationship in which light emitted from the same pixel 110p enters the second region 130b, and a third positional relationship in which light emitted from the same pixel 110p enters the third region 130c. Change the positional relationship between.

As a result, as shown in FIG. 5A, when the color change sheet 130 is used as a reference, the center 110c of a certain pixel 110p is the center of the first region 130a, the center of the second region 130b, and the center of the second region 130b along the X direction. It moves between the centers of three areas 130c. If the arrangement period of the regions 130p in the X direction is Px, the amount of movement of the center 110c of the pixel 110p is 2Px along the X direction. In this case, the drive unit 140 may vibrate the color change sheet 130 along the X direction at the same period.

Note that, as shown in FIG. 5B, the drive unit 140 may move the color change sheet 130 along the Y direction. In this case, if the arrangement period of the regions 130p in the Y direction is Py, the amount of movement of the center 110c of the pixel 110p is 2Py along the Y direction. In this case, the drive unit 140 may vibrate the color change sheet 130 at the same period along the Y direction.

Further, as shown in FIG. 5C, the drive unit 140 may move the color change sheet 130 in an annular manner in the XY plane. In this case, the amount of movement of the center 110c of the pixel 110p is Px along the X direction and Py along the Y direction. Further, the area arranged directly above a certain pixel 110p is repeated in the order of, for example, first area 130a (blue) → second area 130b (green) → third area 130c (red) → second area 130b (green). Change. In this case, the drive unit 140 may move the color-changing sheet 130 in a rectangular shape at the same period, or may move it in a circular motion or an elliptical motion.

Then, when a region of a specific color is placed directly above the pixel 110p, the display device 110 lights up the pixel 110p. For example, by turning on a certain pixel 110p during a period in which the first region 130a (blue) is placed directly above the pixel 110p and turning off the light during other periods, blue color is transmitted from this pixel 110p through the color change sheet 130. can emit light. Further, the pixel 110p is turned on during the period when the first area 130a (blue) is placed directly above the pixel 110p and the period when the second area 130b (green) is placed directly above the pixel 110p, and the second area 130c (red) is placed directly above the pixel 110p. By turning off the light during the period, blue light and green light can be emitted from the pixel 110p via the color change sheet 130. If the cycle in which the drive unit 140 moves the color change sheet 130 is sufficiently short, the viewer 14 will visually recognize a mixture of blue and green. In this way, the drive unit 140 controls each pixel 110p of the display device 110 in a time-sharing manner while changing the positional relationship between the display device 110 and the color change sheet 130, so that a color image can be emitted from the light source unit 11. I can do it.

In this way, light rays L forming a color image are emitted from the color change sheet 130. Based on this image, the imaging optical system 120 of the light source unit 11 forms a first image IM1, which is a real image, at position P. Then, the light forming the first image IM1 is reflected by the reflection unit 12 and the front windshield 13a, and enters the eyebox 14a of the viewer 14.

As a result, as shown in FIG. 6, the viewer 14 visually recognizes the second image IM2, which is a virtual image, on the other side of the front windshield 13a. The second image IM2 can be a color image or a monochrome image. In addition, in FIG. 6, the second image IM2 is shown as a character string "information", but the second image IM2 is not limited to a character string, and may be a figure or the like.

Next, the effects of this embodiment will be explained.
In this embodiment, by changing the positional relationship between the display device 110 and the color change sheet 130 by the drive unit 140, the display device 110 that emits light of a single color and the color change that has a plurality of color regions 130p are configured. Sheet 130 allows color images to be displayed. By making the display device 110 a single-color display device, the light source unit 11 can be downsized, and therefore the video display device 10 can be downsized.

Note that each pixel 110p of the display device 110 is provided with three sub-pixels, and each sub-pixel is provided with an LED element that emits blue light, an LED element that emits green light, and an LED element that emits red light. It is also conceivable that the device 110 displays color images. However, in this case, the number of LED elements is tripled compared to this embodiment, which increases the size and cost of the display device 110. It is also possible to reduce the number of pixels while keeping the number of LED elements the same as in this embodiment. However, in this case, the definition of the image decreases. In contrast, according to the present embodiment, it is possible to realize a small light source unit and an image display device that can display a high-definition color image.

Furthermore, in this embodiment, since the imaging optical system 120 has substantially telecentricity on the first image IM1 side, it is possible to display high-quality images while downsizing the light source unit 11 and the image display device 10. This effect will be explained in detail below.

FIG. 7A is a schematic diagram showing the principle of the light source unit according to this embodiment.
FIG. 7B is a schematic diagram showing the principle of a light source unit according to a reference example.

In FIG. 7A, the light distribution pattern of light emitted from two pixels 110p of the plurality of pixels 110p of the display device 110 in this embodiment is shown by broken lines. Similarly, in FIG. 7B, the light distribution pattern of light emitted from two pixels 2110p of the plurality of pixels 2110p of the display device 2110 in the reference example is shown by broken lines. Further, in FIGS. 7A and 7B, the imaging

optical systems

120 and 2120 are shown in a simplified manner.

As shown in FIG. 7B, in the light source unit 2011 according to the reference example, the display device 2110 is an LCD (Liquid Crystal Display) including a plurality of pixels 2110p. As shown by the broken line in FIG. 7B, the light emitted from each pixel 2110p is mainly distributed in the normal direction of the light exit surface 2110s. Further, although there are many planes including the optical axis of light emitted from one pixel 2110p, in the display device 2110 which is an LCD, the light distribution pattern of light emitted from one pixel 2110p within each plane is mutually different. different. In one of the plurality of planes, the luminous intensity of the light emitted from each pixel 2110p in the direction of the angle θ with respect to the optical axis is approximated by cos ²⁰ θ times the luminous intensity on the optical axis. It has a light distribution pattern.

In such a display device 2110, even if the light is emitted from the same position on the display device 2110, the luminous intensity and chromaticity change depending on the viewing angle of the viewer. Therefore, if the imaging optical system 2120 takes in light emitted from each pixel 2110p in a direction other than the normal direction, even if the brightness of the light emitted from all pixels 2110p is made uniform, the first image In IM1, variations in brightness and chromaticity occur. That is, the quality of the first image IM1 is degraded. Therefore, in order to prevent the quality of the first image IM1 from deteriorating, it is necessary to take in the light emitted from each pixel 2110p of the display device 2110 from the normal direction. As a result, the imaging optical system 2120 becomes larger.

In contrast, in the light source unit 11 according to the present embodiment, the imaging optical system 120 has approximately telecentricity on the first image IM1 side, and the light emitted from the display device 110 has approximately Lambertian light distribution. have Therefore, the quality of the first image IM1 can be improved while reducing the size of the light source unit 11. Specifically, the display device 110 is an LED display having a plurality of LED elements 112, and the light emitted from each LED element 112 via the wavelength conversion member 15 has a substantially Lambertian light distribution. Therefore, the dependence of the luminous intensity and chromaticity of the light emitted from each pixel 110p of the display device 110 on the angle is the same as the dependence of the luminous intensity and chromaticity of the light emitted from each pixel 2110p of the display device 2110 on the angle in the reference example. low compared to In particular, the closer to a strict Lambertian light distribution, that is, the closer n in cos ⁿ θ, which is an approximation formula for the light distribution pattern, approaches 1, the more the luminous intensity and chromaticity of the light emitted from each pixel 110p of the display device 110 becomes , it becomes approximately uniform regardless of the angle. Therefore, as shown in FIG. 7A, even if the imaging optical system 120 takes in the light that has passed through the focal point F, that is, even if it takes in the light from a direction other than the normal direction, the luminance of the first image IM1 It is possible to suppress variations in color and chromaticity and improve the quality of the first image IM1.

Furthermore, since the imaging optical system 120 forms the first image IM1 using light that has mainly passed through the focal point F, it is possible to suppress the optical diameter of the light incident on the imaging optical system 120 from expanding. Thereby, the input element 121 can be miniaturized. Furthermore, the plurality of chief rays L emitted from the output element 123 are substantially parallel to each other. The fact that the plurality of chief rays L emitted from the output element 123 are substantially parallel to each other means that the range to which light contributing to image formation in the output element 123 is irradiated is approximately the same size as the first image IM1. It means that there is. Therefore, the output element 123 of the imaging optical system 120 can also be made smaller. As described above, it is possible to provide a light source unit 11 that can form a small and high-quality first image IM1.

Further, the video display device 10 according to the present embodiment includes a light source unit 11 and a reflection unit 12 that is spaced apart from the light source unit 11 and reflects the light emitted from the imaging optical system 120. The first image IM1 is formed between the light source unit 11 and the reflection unit 12. In such a case, the light emitted from one point on the display device 110 passes through the output element 123 and is then focused at the formation position of the first image IM1. On the other hand, when the first image IM1 is not formed between the light source unit 11 and the reflection unit 12, the optical diameter of the light emitted from one point of the display device 110 is from the input element 121 toward the reflection unit 12. , gradually spread. Therefore, in this embodiment, in the output element 123, the range irradiated with light emitted from one point of the display device 110 can be made smaller compared to the case where the first image IM1 is not formed. Therefore, the output element 123 can be made smaller.

Further, since the light source unit 11 according to the present embodiment is small, when the light source unit 11 is mounted on the vehicle 13 and used as a head-up display, the light source unit 11 can be easily placed in a limited space inside the vehicle 13. can.

Furthermore, the imaging optical system 120 in this embodiment includes a bending section 120a and a direction changing section 120b. In this way, in the imaging optical system 120, by separating the part having the function of making the principal rays L parallel to each other and the part forming the first image IM1 at a desired position, the imaging optical system The design of system 120 is facilitated.

Further, a part of the optical path within the imaging optical system 120 extends in a direction intersecting the XY plane. Therefore, the imaging optical system 120 can be downsized to some extent in the direction along the XY plane. Further, another part of the optical path within the imaging optical system 120 extends in the direction along the XY plane. Therefore, the imaging optical system 120 can be downsized to some extent in the Z direction.

<Example>
Next, light source units according to Examples and Reference Examples will be described.
FIG. 8A is a graph showing a light distribution pattern of light emitted from one light emitting area in Examples 1, 11 and Reference Example.
FIG. 8B is a graph showing the uniformity of brightness of the second image in Examples 1 to 12 and the reference example.

The video display devices according to Examples 1 to 12 and reference examples include a light source unit and a reflection unit, and the light source unit includes a plurality of light emitting areas arranged in a matrix and an imaging optical system. were set on the simulation software. Each light emitting area corresponds to each pixel 110p of the display device 110 in the above embodiment.

In FIG. 8A, the horizontal axis is the angle of the light emitting area with respect to the optical axis, and the vertical axis is the luminous intensity normalized by dividing the luminous intensity at that angle by the luminous intensity on the optical axis. As shown in FIG. 8A, the display device according to the first embodiment has an arrangement in which the luminous intensity of the light emitted from each light emitting area in the direction at an angle θ with respect to the optical axis is expressed as cos θ times the luminous intensity on the optical axis. It was set on the simulation software to have a light pattern. That is, in Example 1, the light emitted from each light emitting area has a strict Lambertian light distribution.

In Examples 2 to 12, the light emitted from each light emitting area has a light distribution pattern in which the luminous intensity in the direction of the angle θ with respect to the optical axis is expressed as cos ⁿ θ times the luminous intensity on the optical axis. It was set on the simulation software. In Example 2, n=2, and n was set to increase by 1 from Example 2 to Example 12.

Further, when the light distribution pattern within one plane of the light emitted from the pixels of the LCD was investigated, it was found that the light distribution pattern was as shown by the thin broken line in FIG. 8A. As described above, it has been found that this light distribution pattern can be approximated to a light distribution pattern in which the luminous intensity in the direction at an angle θ with respect to the optical axis is expressed as cos ²⁰ θ times the luminous intensity on the optical axis. Therefore, in the reference example, the simulation software is set so that the luminous intensity in the direction of angle θ with respect to the optical axis of each light emitting area has a light distribution pattern expressed as cos ²⁰ θ times the luminous intensity on the optical axis. did.

The imaging optical systems in Examples 1 to 12 and Reference Example were all set to have telecentricity on the first image side.

Next, for each of Examples 1 to 12 and Reference Example, the brightness distribution of the second image formed when the brightness of all light emitting areas was kept constant was simulated. At this time, the second image was a rectangle with a long side of 111.2 mm and a short side of 27.8 mm. Furthermore, at this time, the plane on which the second image was formed was divided into square areas having sides of 1 mm, and the brightness value of each area was simulated.

Furthermore, the uniformity of the brightness of the second image at that time was evaluated. Here, "uniformity of brightness" is a value expressed as a percentage of the minimum value to the maximum value of brightness within the second image. The results are shown in FIG. 8B. Note that in FIG. 8B, the horizontal axis represents each example and reference example, and the vertical axis represents the uniformity of brightness.

As shown in FIG. 8B, it was found that as n increases, the uniformity of brightness decreases. This is because the larger n becomes, the lower the brightness at a position away from the center in the second image. In particular, in Example 11, ie, n=11, it was found that the brightness uniformity was 30%. Since the viewer can easily distinguish between the second image and the area where the second image is not formed, it is considered that the uniformity of the brightness of the second image should be 30% or more.

Therefore, when the imaging optical system is configured to have approximately telecentricity, in order to suppress unevenness in brightness between the first image and the second image, the light emitted from the display device must have approximately Lambertian light distribution. It has been found that it is preferable to have Specifically, it has been found that n in cos ⁿ θ, which is an approximate expression of the light distribution pattern, is preferably 11 or less, and even more preferably 1. As described above, as n deviates from 1, the uniformity of the brightness of the second image IM2 decreases, but in order to compensate for such non-uniformity of brightness, the display brightness of the display device 110 is set to a predetermined value in advance. A brightness distribution can be provided. For example, if the light emitted from each pixel 110p of the display device 110 passes through the imaging optical system 120, and the brightness at the outer edge of the second image IM2 tends to be lower than the brightness at the center, the display device 110 The display device 110 may be controlled so that the output of the LED element 112 of the pixel 110p on the outer edge side is larger than the output of the LED element 112 of the pixel 110p on the center side.

<First modification of the first embodiment>
Next, a first modification of the first embodiment will be described.
FIG. 9A is a plan view showing a color changing sheet of a light source unit according to this modification.
9B and 9C are plan views showing changes in the positional relationship between the pixels of the display device and the area of the color change sheet in this modification.

In the first embodiment described above, an example was described in which white light is emitted from the pixel 110p of the display device 110, and light of three colors, blue, green, and red, is emitted from the color change sheet 130, but this modification In the example, an example will be described in which two colors of light, green and red, are emitted from the color change sheet 130e.

As shown in FIG. 9A, also in the color change sheet 130e in this modification, a plurality of regions 130p are arranged in a matrix along the first direction and the second direction. There are two types of regions 130p: a first region 130a and a second region 130b. The first regions 130a and the second regions 130b are arranged alternately along the first direction (X direction) and the second direction (Y direction).

In this modification, the first region 130a is made of a green film, and the first color is green. The second region 130b is made of a red film, and the second color is red. That is, white light is incident on the first region 130a from the pixel 110p of the display device 110. The first region 130a transmits the green component of this white light and blocks other components. Therefore, the first region 130a emits green light. White light is incident on the second region 130b from the pixel 110p. The second region 130b transmits the red component of this white light and blocks other components. Therefore, the second region 130b emits red light.

As shown in FIG. 9B, when the color change sheet 130e is used as a reference, the center 110c of a certain pixel 110p moves between the center of the first region 130a and the center of the second region 130b along the X direction. . The amount of movement of the center 110c of the pixel 110p is Px along the X direction. Alternatively, as shown in FIG. 9C, the drive unit 140 may move the color change sheet 130e along the Y direction. In this case, the amount of movement of the center 110c of the pixel 110p is Py along the Y direction.

According to this modification, when only two colors, green and red, are required to display an image, the light source unit can be made smaller compared to the first embodiment. Furthermore, compared to the first embodiment, the time period during which the region 130p of a desired color is placed directly above a certain pixel 110p is longer, so the brightness of the image is improved. The configuration, operation, and effects of this modification other than those described above are the same as those of the first embodiment.

<Second modification of the first embodiment>
Next, a second modification of the first embodiment will be described.
FIG. 10 is a plan view showing a color changing sheet of a light source unit according to this modification.
In this modification, an example will be described in which the color change sheet 130f is provided with a transparent area.

As shown in FIG. 10, also in the color changeable sheet 130f in this modification, the first region 130a and the second region 130b are arranged alternately along the first direction (X direction) and the second direction (Y direction). has been done.

In this modification, the first region 130a is made of a transparent film. Therefore, the first region 130a substantially transmits the white light emitted from the pixel 110p of the display device 110 as it is. Therefore, the first color is white. Note that the first region 130a may not be provided with a transparent film and may be an opening. The second region 130b is made of a blue film, and the second color is blue. Note that in FIG. 10, the transparent first region 130a is labeled with the letter "C".

According to this modification, images in two colors, white and blue, can be displayed. Note that the second region 130b may be made of a green film or a red film. In these cases, the second color will be green or red, respectively. The configuration, operation, and effects of this modification other than those described above are the same as those of the first modification.

<Second embodiment>
Next, a second embodiment will be described.
FIG. 11 is an end view showing the display device of the video display device according to this embodiment.
FIG. 12 is a plan view showing the color changing sheet of the light source unit according to this embodiment.

In the first embodiment described above, an example was described in which white light is emitted from the pixels 110p of the display device 110 and the color change sheet 130 is a color film, but in this embodiment, the pixels 110p of the display device 110 An example in which blue light is emitted from 110p and the color change sheet 230 is a phosphor sheet will be described.

As shown in FIG. 11, in this embodiment, the wavelength conversion member 115 is not provided in the display device 110, and a plurality of recesses 112t are provided in the light emitting surface 112s of the LED element 112. As a result, the light emitted from the LED element 112 has a substantially Lambertian light distribution. The LED element 112 emits blue light. Therefore, blue light is emitted from the pixel 110p.

As shown in FIG. 12, in this embodiment, the color change sheet 230 is provided with a plurality of regions 230p. The shape, size, and arrangement period of the region 230p are approximately the same as the shape, size, and arrangement period of the pixels 110p of the display device 110. The region 230p includes a first region 230a, a second region 230b, and a third region 230c.

The first region 230a is made of a transparent film. Blue light is incident on the first region 230a from the pixel 110p of the display device 110. The first region 230a transmits this blue light and emits it substantially unchanged. Therefore, the light emitted from the first region 230a is blue light, and the first color is blue.

The second region 230b is composed of a phosphor layer. The second region 230b includes a phosphor that absorbs light emitted from the pixel 110p and emits green light. As a result, blue light is incident on the second region 230b from the pixel 110p of the display device 110, and the phosphor absorbs this blue light and emits green light. Therefore, the second color is green. The light emitted from the second region 230b has a substantially Lambertian light distribution.

The third region 230c is also composed of a phosphor layer. The third region 230c includes a phosphor that absorbs light emitted from the pixel 110p and emits red light. As a result, blue light enters the third region 230c from the pixel 110p of the display device 110, and the phosphor absorbs this blue light and emits red light. Therefore, the third color is red. The light emitted from the third region 230c also has a substantially Lambertian light distribution.

In this embodiment, blue light emitted from the LED elements 112 is incident on the first region 230a of the color change sheet 230. The first region 230a transmits the incident blue light as it is and emits it, so the light utilization efficiency is high. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the first embodiment.

<First modification of the second embodiment>
Next, a first modification of the second embodiment will be described.
FIG. 13 is a plan view showing a color changing sheet of a light source unit according to this modification.

In the second embodiment, an example has been described in which blue light is emitted from the pixel 110p of the display device 110, and light of three colors, blue, green, and red, is emitted from the color change sheet 230. An example will be described in which blue light is emitted from the pixel 110p and two colors of green and red light are emitted from the color change sheet 230e.

As shown in FIG. 13, also in the color change sheet 230e in this modification, the first region 230a and the second region 230b are arranged alternately along the first direction (X direction) and the second direction (Y direction). has been done. The first region 230a and the second region 230b are composed of a phosphor layer. The first region 230a includes a phosphor that absorbs blue light and emits green light. The second region 230b includes a phosphor that absorbs blue light and emits red light. Therefore, in this modification, the first color is green and the second color is red. The operation of the drive unit 140 in this modification, that is, the change in the positional relationship between the display device 110 and the color change sheet 230e is as shown in FIG. 9B or FIG. 9C.

According to this modification, when only two colors, green and red, are required to display an image, the light source unit can be made smaller compared to the second embodiment. Furthermore, compared to the second embodiment, the time period during which the region 230p of a desired color is placed directly above a certain pixel 110p is longer, so the brightness of the image is improved. The configuration, operation, and effects of this modification other than those described above are the same as those of the second embodiment.

<Second modification of second embodiment>
Next, a second modification of the second embodiment will be described.
FIG. 14 is a plan view showing a color changing sheet of a light source unit according to this modification.
In this modification, an example will be described in which the color change sheet 230f is provided with a transparent area.

As shown in FIG. 14, in the color change sheet 230f in this modification, the first region 230a is made of a transparent film. Therefore, the first region 230a substantially transmits the blue light emitted from the pixel 110p of the display device 110 as is. Therefore, the first region 230a emits blue light. Therefore, the first color is blue. Note that the first region 230a may not be provided with a transparent film and may be an opening. The second region 230b is constituted by a phosphor layer, and includes a phosphor that absorbs blue light and emits green light. Therefore, the second color is green.

According to this modification, images in two colors, blue and green, can be displayed. Note that the second region 230b may include a phosphor that absorbs blue light and emits green light, or may include a phosphor that absorbs blue light and emits red light. Often, it may include a phosphor that absorbs blue light and emits yellow light. In these cases, the second color will be green, red or yellow, respectively. The configuration, operation, and effects of this modification other than those described above are the same as those of the first modification of the second embodiment.

<Third embodiment>
Next, a third embodiment will be described.
FIG. 15 is a plan view showing the color changing sheet of the light source unit according to this embodiment.
In the second embodiment described above, an example in which blue light is emitted from the pixel 110p of the display device 110 has been described, but in this embodiment, an example in which ultraviolet light is emitted from the pixel 110p in the display device 110 will be described. .

As shown in FIG. 15, in this embodiment, the color change sheet 230g is provided with a first region 230a, a second region 230b, and a third region 230c. The first region 230a, the second region 230b, and the third region 230c are each composed of a phosphor layer. The first region 230a includes a phosphor that absorbs ultraviolet light and emits blue light. Therefore, the first color is blue. The second region 230b includes a phosphor that absorbs ultraviolet light and emits green light. Therefore, the second color is green. The third region 230c includes a phosphor that absorbs ultraviolet light and emits red light. Therefore, the third color is red. The light emitted from the first region 230a, second region 230b, and third region 230c has approximately Lambertian light distribution.

In this embodiment, all colors can be adjusted by the phosphor, so color selectivity is high. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the second embodiment.

<Modification of the third embodiment>
Next, a modification of the third embodiment will be described.
FIG. 16 is a plan view showing a color changing sheet of a light source unit according to this modification.
In the third embodiment, an example was described in which ultraviolet light is emitted from the pixel 110p of the display device 110, and light in three colors of blue, green, and red is emitted from the color change sheet 230g, but in this modified example, An example in which two colors of light are emitted from the color change sheet 230h will be described.

As shown in FIG. 16, in the color change sheet 230h in this modification, the first region 230a and the second region 130b are arranged in the first direction (X direction) and the second direction, similarly to the color change sheet shown in FIG. They are arranged alternately along the (Y direction). The first region 230a includes a phosphor that absorbs ultraviolet light and emits light of a first color. The second region 230b includes a phosphor that absorbs ultraviolet light and emits light of a second color. In the example shown in FIG. 16, the first color is blue and the second color is green.

The combination of the first color and the second color is not limited to blue and green, and may be, for example, blue and red, blue and yellow, or green and red. The operation of the drive unit 140 in this modification, that is, the change in the positional relationship between the display device 110 and the color change sheet 230h is as shown in FIG. 9B or 9C.

According to this modification, when only two colors are required to display an image, the light source unit can be made smaller compared to the third embodiment. Furthermore, the brightness of the image is improved compared to the third embodiment. The configuration, operation, and effects of this modification other than those described above are the same as those of the third embodiment.

FIG. 17 is a diagram showing the relationship between the color of light emitted from the pixels of the display device and the configuration of each region of the color change sheet.
As shown in FIG. 17, in the first to third embodiments and their modifications, the light emitted from the pixel 110p of the display device 110 is white light, blue light, or ultraviolet light, and the color changes. An example has been described in which each region of the sheet is a colored or transparent film, or a phosphor layer that emits light of a different color.

However, the present invention is not limited to the example shown in FIG. 17. For example, the color of the light emitted from the color change sheet is not limited to white, blue, green, red, and yellow, but may be other colors such as orange, pink, cyan, and magenta. Further, the number of colors of light emitted from the color change sheet is not limited to two or three colors, and may be four or more colors.

<Fourth embodiment>
Next, a fourth embodiment will be described.
FIG. 18 is a plan view showing the color changing sheet of the light source unit according to this embodiment.

As shown in FIG. 18, in the present embodiment, in the color change sheet 330, two second regions 330b that emit green light are arranged diagonally in the minimum units 330u arranged in two rows and two columns adjacent to each other. One first region 330a that emits blue light and one third region 330c that emits red light are arranged. The color change sheet 330 may be composed of a color film as in the first embodiment, or may be composed of a phosphor sheet as in the second and third embodiments, and may include a transparent area. It's okay to stay.

The operation of the drive unit 140 in this embodiment, that is, the change in the positional relationship between the display device 110 and the color change sheet 330 is as shown in FIG. 5C. As a result, the areas arranged directly above a certain pixel 110p are arranged in the order of, for example, first area 330a (blue) → second area 330b (green) → third area 330c (red) → second area 330b (green). Change repeatedly. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the first embodiment.

<Fifth embodiment>
Next, a fifth embodiment will be described.
FIG. 19 is a plan view showing the color changing sheet of the light source unit according to this embodiment.

As shown in FIG. 19, in the present embodiment, in the color change sheet 430, a first region 430a, a second region 430b, and a third region 430c are repeatedly arranged along the first direction (X direction). . On the other hand, along the second direction (Y direction), regions of the same type are consecutively arranged. The operation of the drive unit 140 in this embodiment, that is, the change in the positional relationship between the display device 110 and the color change sheet 430 is as shown in FIG. 5A. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the first embodiment.

<Sixth embodiment>
Next, a sixth embodiment will be described.
FIG. 20 is a plan view showing the color changing sheet of the light source unit according to this embodiment.

As shown in FIG. 20, in the present embodiment, in the color change sheet 530, a first region 530a, a second region 530b, and a third region 530c are repeatedly arranged along the second direction (Y direction). . On the other hand, along the first direction (X direction), regions of the same type are consecutively arranged. The operation of the drive unit 140 in this embodiment, that is, the change in the positional relationship between the display device 110 and the color change sheet 530 is as shown in FIG. 5B. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the first embodiment.

<Seventh embodiment>
Next, a seventh embodiment will be described.
FIG. 21 is an end view showing the video display device according to this embodiment.
FIG. 22 is a schematic diagram showing the scenery seen from the viewer in the driver's seat in this embodiment.

As shown in FIG. 21, an automobile 1000 according to the present embodiment includes a vehicle 13 and a video display device 20 fixed to the vehicle 13. The video display device 20 includes a light source unit 11 and a reflection unit 22. The video display device 20 according to the present embodiment differs from the first embodiment in that the mirror surface 322a of the mirror 322 of the reflection unit 22 also serves as a reflection surface that allows the viewer 14 to view the second image IM2. This is different from the video display device 10.

The configuration of the light source unit 11 in the video display device 20 is the same as that in the first embodiment. The light source unit 11 is arranged on the ceiling part 13b of the vehicle 13. The reflection unit 22 is arranged on the dashboard section 13c of the vehicle 13. Reflection unit 22 has a mirror 322. The mirror surface 322a of the mirror 322 is, for example, a concave surface. The mirror surface 322a is arranged at a position and at an angle facing the eye box 14a of the viewer 14 when the viewer 14 is in the driver's seat of the vehicle 13. For example, the mirror surface 322a faces in a direction between the -X direction (rearward) and the +Z direction (upward). The angle of this mirror surface 322a can be finely adjusted depending on the position of the eyebox 14a of the viewer 14.

Next, the operation of this embodiment will be explained.
The principal ray L emitted from the light source unit 11 travels in a direction between the +X direction (front) and the -Z direction (downward), is reflected at the mirror surface 322a of the mirror 322 of the reflection unit 22, and travels in the -X direction ( The light travels in a direction between the +Z direction (upward) and the +Z direction (upwards) and enters the eyebox 14a of the viewer 14. The path of the chief ray L from the light source unit 11 toward the reflection unit 12 is located inside the front windshield 13a of the vehicle 13, and generally follows the front windshield 13a. The chief ray L forms a first image IM1 at a position P between the light source unit 11 and the reflection unit 22. At this time, the drive unit 140 changes the positional relationship between the display device 110 and the color change sheet 130, and the display device 110 is controlled in a time-sharing manner, thereby changing the first image IM1 into a color image including a plurality of colors. do.

Thereby, as shown in FIGS. 21 and 22, the viewer 14 can visually recognize the second image IM2, which is a virtual image, behind the mirror surface 322a of the dashboard portion 13c. The second image IM2 is formed far away from the mirror surface 322a, for example, 3 m ahead. Therefore, the viewer 14 can view the second image IM2 without significantly changing the focal length of his eyes from a state where he is viewing a distant scene through the front windshield 13a.

Next, the effects of this embodiment will be explained.
The video display device 20 according to this embodiment is divided into a light source unit 11 and a reflection unit 22, and is fixed at different positions in the vehicle 13, similarly to the first embodiment. The video display device 20 requires a long optical path length in order to form the second image IM2 at a position several meters in front of the vehicle. Part of the optical path length can be configured using the thirteen internal spaces. This eliminates the need to form the entire required optical path length inside the video display device 20, and the video display device 20 can be made smaller.

Furthermore, in the video display device 20, only the mirror 322 is provided in the reflection unit 22. Thereby, the configuration of the reflection unit 22 can be simplified, and the reflection unit 22 can be made smaller.

Further, by using the mirror surface 322a disposed on the dashboard portion 13c as a reflective surface, the viewer 14 can reliably view the second image IM2 without being affected by the background of the reflective surface. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the first embodiment.

Incidentally, the mirror 322 of the reflection unit 22 may be constituted by a half mirror or a transparent plate. Even in this case, by keeping the inside of the dashboard portion 13c dark, it is possible to prevent the viewer 14 from seeing the inside of the dashboard portion 13c. Alternatively, the mirror surface 322a of the mirror 322 may be black enough to sufficiently reflect the chief ray L emitted from the light source unit 11. Thereby, it is possible to suppress a decrease in visibility due to reflection of external light or the like by the mirror surface 322a of the mirror 322. Further, the mirror 322 may be arranged continuously with the surface of the dashboard portion 13c. This eliminates the need to make a hole in the dashboard portion 13c, and improves the design of the interior of the automobile 1000.

<Eighth embodiment>
Next, an eighth embodiment will be described.
FIG. 23 is an end view showing the video display device according to this embodiment.
FIG. 24 is an enlarged cross-sectional view of a part of the display device and reflective polarizing element shown in FIG. 23.

As shown in FIGS. 23 and 24, a video display device 70A according to the present embodiment differs from the first embodiment in that it includes a display device 710A instead of the display device 110 and further includes a reflective polarizing element 740. This is different from the video display device 10. The display device 710A in this embodiment is different from the display device in the first embodiment in that the light exit surface of the LED element 712 is generally flat, and further includes a protective layer 714, a wavelength conversion member 715, and a light scattering member 716A. It is different from 110. The other configuration of the display device 710A is the same as the display device 110 in the first embodiment. Further, the light source unit 71A according to the present embodiment includes a color change sheet 130 and a drive unit 140 similarly to the light source unit 11 according to the first embodiment. However, in FIG. 23, illustration of the color change sheet 130 and the drive unit 140 is omitted.

The protective layer 714 covers the plurality of LED elements 712 arranged in rows and columns. The protective layer 714 is made of, for example, a polymer material having a sulfur (S)-containing substituent or a phosphorus (P) atom-containing group, or a high refractive material in which inorganic nanoparticles with a high refractive index are introduced into a polymer matrix such as polyimide. Transparent materials such as composite nanocomposite materials can be used.

The wavelength conversion member 715 is arranged on the protective layer 714. The wavelength conversion member 715 includes one or more wavelength conversion materials such as a general phosphor material, a perovskite phosphor material, or a quantum dot (QD). The light emitted from each LED element 712 enters the wavelength conversion member 715. When the light emitted from each LED element 712 enters the wavelength conversion material included in the wavelength conversion member 715, the wavelength conversion material emits light having an emission peak wavelength different from the emission peak wavelength of each LED element 712. The light emitted by the wavelength conversion member 715 has a substantially Lambertian light distribution.

The light scattering member 716A includes, for example, a translucent resin member and light scattering particles or holes arranged in the resin member. Examples of the resin member include polycarbonate. Examples of light-scattering particles include materials that have a refractive index difference with the resin member, such as titanium oxide. Note that the light scattering member 716A may obtain a light scattering effect by roughening its surface to provide unevenness.

As the reflective polarizing element 740, for example, a multilayer thin film laminated polarizing plate in which thin film layers having different polarization characteristics are laminated can be used. Reflective polarizing element 740 is placed on display device 710A. In this embodiment, the reflective polarizing element 740 is placed on the light scattering member 716A. Therefore, the light emitted from the LED element 712 and the wavelength conversion member 715 enters the reflective polarizing element 740. The reflective polarizing element 740 transmits the first polarized light 710p of the light emitted from the display device 710A, and reflects the second polarized light 710s toward the display device 710A. The direction of vibration of the electric field of the second polarized light 710s is approximately orthogonal to the direction of vibration of the electric field of the first polarized light 710p.

In this embodiment, the first polarized light 710p is P polarized light, and the second polarized light 710s is S polarized light. Here, "P-polarized light" means light whose electric field vibration direction is substantially parallel to the XY plane. Moreover, "S-polarized light" means light whose electric field vibration direction is approximately perpendicular to the XY plane including incident light and reflected light.

The viewer 14 driving the vehicle 13 may wear polarized sunglasses 14b in order to reduce the glare of sunlight that is reflected from a puddle in front of the vehicle 13 and transmitted through the front windshield 13a. In this case, the component corresponding to P-polarized light when viewed from the front windshield 13a is particularly reduced in sunlight reflected by a puddle or the like, so the polarized sunglasses 14b blocks most of the S-polarized light. Designed to be. Therefore, when the viewer 14 wears the polarized sunglasses 14b, most of the S-polarized light included in the light emitted by the display device 710A is also blocked by the polarized sunglasses 14b, so that the viewer 14 cannot visually recognize the second image IM2. It may become difficult. Note that P-polarized light and S-polarized light in this specification are physically defined by the presence of a reflective object such as the above-mentioned puddle.

In this embodiment, the reflective polarizing element 740 transmits the first polarized light 710p of the light emitted from the display device 710A and reflects the second polarized light 710s. Most of the first polarized light 710p transmitted through the reflective polarizing element 740 passes through the imaging optical system 120, the reflective unit 12, and the inner surface of the front windshield 13a, and then passes through the eye box without being blocked by the polarized sunglasses 14b. 14a. Note that the incident angle of the first polarized light 710p when it enters the inner surface of the front windshield 13a is set to be an angle different from the Brewster angle.

Specifically, as shown in FIG. 24, the light emitted from the LED element 712 is irradiated onto the wavelength conversion member 715. As a result, the wavelength conversion member 715 is excited and emits light having a peak emission wavelength longer than the peak emission wavelength of the light emitted from the LED element 712. In this embodiment, the light emitted from the display device 710A includes light emitted from the LED element 712 and light emitted from the wavelength conversion member 715. Hereinafter, of the light emitted from the display device 710A, the light emitted from the LED element 712 is also referred to as "short wavelength light", and the light emitted from the wavelength conversion member 715 is also referred to as "long wavelength light". However, most of the light emitted from the LED element 712 may be absorbed by the wavelength conversion member 715.

Most of the first polarized light 710p included in these short wavelength lights and long wavelength lights passes through the reflective polarizing element 740 and exits from the imaging optical system 120. Furthermore, most of the second polarized light 710s included in these short wavelength lights and long wavelength lights is reflected by the reflective polarizing element 740. A portion of the second polarized light 710s reflected by the reflective polarizing element 740 is scattered and reflected by components of the display device 710A, such as the light scattering member 716A and the wavelength conversion member 715. Due to scattered reflection, a portion of the second polarized light 710s is converted into the first polarized light 710p. A part of the first polarized light 710p converted from the second polarized light 710s passes through the reflective polarizing element 740 and is emitted from the light source unit 71A. Therefore, the brightness of the first image IM1 can be improved while increasing the proportion of the first polarized light 710p included in the light emitted from the light source unit 71A. By improving the brightness of the first image IM1, the brightness of the second image IM2 also improves. This makes it easier for the viewer 14 to visually recognize the second image IM2.

Further, a part of the short wavelength light included in the second polarized light 710s may be reflected by the reflective polarizing element 740 and then enter the wavelength conversion member 715. In this case, an effect can be expected in which the wavelength conversion member 715 absorbs the short wavelength light of the second polarized light 710s and newly emits long wavelength light. Both the scattered reflected light and the emitted light have approximately Lambertian light distribution. Further, the reflective polarizing element 740 itself may scatter and reflect the second polarized light 710s. Also in this case, a portion of the second polarized light 710s is converted into the first polarized light 710p due to scattering and reflection.

In this embodiment, one reflective polarizing element 740 covers all pixels of the display device 710A. However, the light source unit may include a plurality of reflective polarizing elements, and each reflective polarizing element may be arranged on each pixel. Further, the configuration of the display device used in combination with the reflective polarizing element is not limited to the above. For example, by using the light scattering and reflection effect of the wavelength conversion member, the display device may be configured without the light scattering member. Furthermore, by using the scattering and reflection effect of the light scattering member, the display device may be configured without the wavelength conversion member. Further, as in the first embodiment, by using the light scattering and reflection effect by the plurality of recesses or the plurality of convexes provided on the light emitting surface of the LED element, the display device can be converted into a wavelength converting member and a light scattering member. A configuration in which neither is provided may be used.

Next, the effects of this embodiment will be explained.
The light source unit 71A according to the present embodiment is arranged on the display device 710A, transmits the first polarized light 710p of the light emitted from the display device 710A, and transmits the second polarized light 710s of the light emitted from the display device 710A. It further includes a reflective polarizing element 740 that reflects. Therefore, the brightness of the first image IM1 can be improved while increasing the proportion of the first polarized light 710p included in the light emitted from the light source unit 71A.

Furthermore, the light emitted from the reflective polarizing element 740 also has a substantially Lambertian light distribution. Therefore, also in this embodiment, it is possible to provide the light source unit 71A that can form the first image IM1 that is small and of high quality. Note that since the plurality of LED elements 712 are discretely mounted on the substrate 111, a grainy appearance may occur in the first image IM1. The wavelength conversion member 715 has the effect of alleviating this graininess. The light scattering member 716A can further enhance the effect of alleviating this graininess. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the first embodiment.

<Ninth embodiment>
Next, a ninth embodiment will be described.
FIG. 25 is a side view showing the light source unit according to this embodiment.
As shown in FIG. 25, in a video display device 70B according to the present embodiment, a light source unit 71B includes a display device 710A having a configuration similar to that of the eighth embodiment instead of the display device 110, and a reflective polarizing element 750. The video display device 10 is different from the video display device 10 according to the first embodiment in that it further includes a light shielding member 760. Note that in FIG. 25, only the light shielding member 760 is shown in cross section.

As the reflective polarizing element 750, for example, a wire grid type reflective polarizing element using a plurality of metal nanowires can be used. The reflective polarizing element 750 is arranged in a portion of the optical path from the display device 710A to the reflective unit 12, where the plurality of principal rays L are substantially parallel to each other. In this embodiment, the plurality of principal rays L are substantially parallel to each other in the optical path between the intermediate element 122 and the reflection unit 12, and the reflective polarizing element 750 is arranged between the intermediate element 122 and the output element 123. be done.

The reflective polarizing element 750 transmits the first polarized light 710p, which is P-polarized light, and reflects the second polarized light 710s, which is S-polarized light, back to the display device 710A. Specifically, light 710a including first polarized light 710p and second polarized light 710s is emitted from display device 710A. This light 710a enters the reflective polarizing element 750 after passing through the input element 121 and the intermediate element 122.

The reflective polarizing element 750 transmits most of the first polarized light 710p included in this light 710a. Most of the first polarized light 710p that has passed through the reflective polarizing element 750 is output from the reflective unit 12 after passing through the output element 123.

The reflective polarizing element 750 reflects most of the second polarized light 710s included in this light 710a so as to return along the optical path from the display device 710A to the reflective polarizing element 750. Specifically, the shape of the reflective polarizing element 750 is a flat plate. The reflective polarizing element 750 is arranged so as to be substantially perpendicular to the principal ray L. The reflective polarizing element 750 specularly reflects most of the second polarized light 710s. Therefore, most of the second polarized light 710s reflected by the reflective polarizing element 750 passes through the intermediate element 122 and the input element 121 in this order, and then returns to the display device 710A.

A part of the second polarized light 710s that has returned to the display device 710A is scattered and reflected by components of the display device 710A, such as the light scattering member 716A and the wavelength conversion member 715. Due to scattered reflection, a portion of the second polarized light 710s is converted into the first polarized light 710p. A part of the first polarized light 710p converted from the second polarized light 710s passes through the reflective polarizing element 750 after passing through the input element 121 and the intermediate element 122. Most of the first polarized light 710p that has passed through the reflective polarizing element 750 is output from the reflective unit 12 after passing through the output element 123. Therefore, the brightness of the second image IM2 can be improved while increasing the proportion of the first polarized light 710p included in the light emitted from the video display device 70B. This makes it easier for the viewer 14 to visually recognize the second image IM2.

Further, a portion of the short wavelength light included in the second polarized light 710s returned to the display device 710A may be irradiated onto the wavelength conversion member 715, as in the eleventh embodiment. In this case, as in the eleventh embodiment, the effect can be expected that the wavelength conversion member 715 absorbs the short wavelength light of the second polarized light 710s and newly emits long wavelength light.

The light shielding member 760 is arranged between the display device 710A and the input element 121 of the imaging optical system 120. The shape of the light shielding member 760 is, for example, a flat plate substantially parallel to the XY plane. The light shielding member 760 is provided with an opening 761 that penetrates the light shielding member 760 in the Z direction. The focal point F of the imaging optical system 120 is located within the aperture 761.

Of the light emitted from the display device 710A, the light that passes through the focal point F and its vicinity passes through the opening 761 of the light shielding member 760 and enters the input element 121, and most of the other light passes through the light shielding member 760. is blocked by. Further, among the second polarized light 710s reflected by the reflective polarizing element 750, the light along the optical path, that is, the light passing through the focal point F and its vicinity, passes through the opening 761 of the light shielding member 760 and returns to the display device 710A. On the other hand, most of the second polarized light 710s reflected by the reflective polarizing element 750, which does not go along the optical path but goes toward the display device 710A, is blocked by the light shielding member 760.

Next, the effects of this embodiment will be explained.
The video display device 70B according to this embodiment further includes a reflective polarizing element 750. The reflective polarizing element 750 is configured so that, in the optical path from the display device 710A to the reflection unit 12, a plurality of chief rays L that are emitted from different positions in the display device 710A and pass through the first image IM1 are substantially parallel to each other. The first polarized light 710p of the light emitted from the display device 710A is transmitted therethrough, and the second polarized light 710s of the light emitted from the display device 710A is reflected back to the display device 710A. Therefore, the brightness of the second image IM2 can be improved while increasing the proportion of the first polarized light 710p included in the light emitted from the video display device 70B.

Furthermore, a light shielding member 760 is provided between the display device 710A and the input element 121. The light shielding member 760 is provided with an opening 761 through which the second polarized light 710s returning to the display device 710A along the optical path passes. Therefore, while allowing the light along the optical path of the second polarized light 710s reflected by the reflective polarizing element 750 to return to the display device 710A, the light along the optical path of the second polarized light 710s reflected by the reflective polarizing element 750 is allowed to return to the display device 710A. Stray light that does not follow the direction can be suppressed from heading toward the display device 710A. Thereby, the quality of the first image IM1 and the second image IM2 can be improved. In addition, due to the light shielding member 760, stray light out of the light emitted from the display device 710A that does not follow the optical path is reflected by the reflective polarizing element 750 and the optical elements of the imaging optical system 120, and heads toward the display device 710A. It is possible to suppress re-excitation and scattering reflection in places where it is not possible.

Note that the light shielding member 760 may not be provided in the video display device 70B. Further, the reflective polarizing element 740 described in the third embodiment may be further provided on the display device 710A of the video display device 70B. In such a case, the second polarized light 710s that was not completely reflected by the reflective polarizing element 740 on the display device 710A can be reflected by the reflective polarizing element 750. Therefore, the brightness of the second image IM2 can be improved while increasing the proportion of the first polarized light 710p included in the light emitted from the video display device 70B. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the third embodiment.

<Modification of the ninth embodiment>
Next, a modification of the ninth embodiment will be described.
FIG. 26 is a side view showing a light source unit according to this modification.
Also in FIG. 26, only the light shielding member 760 is shown in cross section.

As shown in FIG. 26, in this modification, a reflective polarizing element 750 is arranged between the output element 123 and the reflective unit 12. Note that although FIG. 26 shows an example in which the reflective polarizing element 750 is located between the output element 123 and the first image IM1, the reflective polarizing element 570 is positioned between the first image IM1 and the reflective unit 12. may be placed between. The configuration, operation, and effects of this modification other than those described above are the same as those of the ninth embodiment.

Each of the above-described embodiments and modifications thereof are examples that embody the present invention, and the present invention is not limited to these embodiments and modifications. For example, the present invention includes additions, deletions, or changes of some components or steps in each of the above-described embodiments and modifications. Further, each of the embodiments and modifications described above can be implemented in combination with each other.

The embodiment includes the following aspects.

(Additional note 1)
a display device having multiple pixels and capable of displaying an image;
a color-changing sheet on which light emitted from the display device enters;
an input element into which light emitted from the color change sheet is incident; and an output element into which light that has passed through the input element is incident; the light emitted from the output element forms a first image corresponding to the image; an imaging optical system that forms
a drive unit that changes the positional relationship between the display device and the color change sheet;
Equipped with
The color change sheet is
a first region into which light enters from the pixel and emits light of a first color;
a second region into which light enters from the pixel and emits light of a second color different from the first color;
has
The drive unit sets the positional relationship between the display device and the color change sheet to a first positional relationship in which light emitted from one of the pixels enters the first area, and a first positional relationship in which light emitted from one of the pixels enters the first area. changing between a second positional relationship of incidence on the second region,
The imaging optical system has substantially telecentricity on the first image side,
A light source unit in which light emitted from the display device has a substantially Lambertian light distribution.

(Additional note 2)
The color of the light emitted from the pixel is the first color,
The light source unit according to supplementary note 1, wherein the first region transmits light incident from the pixel.

(Additional note 3)
The light source unit according to

appendix

1 or 2, wherein the second region transmits light of the second color out of the light emitted from the pixel.

(Additional note 4)
The light source unit according to

appendix

1 or 2, wherein the second region includes a phosphor that absorbs light emitted from the pixel and emits light of the second color.

(Appendix 5)
The color change sheet further includes a third region into which light enters from the pixel and emits light of a third color different from the first color and the second color,
The drive unit determines the positional relationship between the display device and the color change sheet according to the first positional relationship, the second positional relationship, and the light emitted from the one pixel entering the third area. The light source unit according to any one of Supplementary Notes 1 to 4, wherein the light source unit is changed between the third positional relationship.

(Appendix 6)
In the display device, the plurality of pixels are arranged along a first direction and a second direction crossing the first direction,
The light source unit according to appendix 5, wherein in the color change sheet, the first region, the second region, and the third region are arranged along the first direction.

(Appendix 7)
In the display device, the plurality of pixels are arranged along a first direction and a second direction crossing the first direction,
In the color change sheet, the first region and the second region are arranged along the first direction, and the first region and the third region are arranged along the second direction. The light source unit according to supplementary note 5.

(Appendix 8)
The light emitted from the display device has a light distribution pattern in which the luminous intensity in a direction at an angle θ with respect to the optical axis of the light emitted from the display device is approximated by cos ⁿ θ times the luminous intensity on the optical axis. ,
The light source unit according to any one of Supplementary Notes 1 to 7, wherein the n is a value larger than 0.

(Appendix 9)
The light source unit according to appendix 8, wherein n is 11 or less.

(Appendix 10)
The light source unit according to any one of appendices 1 to 9, wherein the display device is an LED display having a plurality of LED elements.

(Appendix 11)
The light source unit according to appendix 10, wherein the light emitted from the LED element has a substantially Lambertian light distribution.

(Appendix 12)
The light source unit according to

Supplementary Note

10 or 11, wherein the display device further includes a wavelength conversion member disposed on the LED element and into which light emitted from the LED element enters.

(Appendix 13)
The imaging optical system includes a bending section including the input element, and a direction changing section including the output element,
The bending portion is configured such that a plurality of chief rays exit from different positions in the display device and cross each other to reach the first image before entering the input element, before and after the first image. bending the plurality of chief rays so that they become substantially parallel;
Any one of Supplementary Notes 1 to 12, wherein the direction changing unit changes the traveling direction of the plurality of chief rays so that the plurality of chief rays that have passed through the bending part head toward the formation position of the first image. The light source unit described in.

(Appendix 14)
An opening is provided between the display device and the imaging optical system, through which a portion of light directed from the display device to the imaging optical system passes, and is directed from the display device to the imaging optical system. The light source unit according to any one of Supplementary Notes 1 to 13, further comprising a light shielding member that blocks another part of the light.

(Appendix 15)
A light source unit according to any one of Supplementary Notes 1 to 14,
a reflection unit that is separated from the light source unit and reflects the light emitted from the imaging optical system;
Equipped with
The first image is an image display device formed between the light source unit and the reflection unit.

(Appendix 16)
The display device is arranged on an optical path from the display device to the reflection unit, transmits the first polarized light of the light emitted from the display device, and transmits the second polarized light of the light emitted from the display device to the display device. 16. The video display device according to appendix 15, further comprising a reflective polarizing element that reflects light back to .

(Appendix 17)
vehicle and
the video display device according to supplementary note 15 or 16 fixed to the vehicle;
A car equipped with.

The present invention can be used, for example, in a head-up display.

10: Video display device 11: Light source unit 12: Reflection unit 13: Vehicle 13a: Front windshield 13b: Ceiling section 13c: Dashboard section 13h1, 13h2: Through holes 13s1, 13s2: Wall 14: Viewer 14a: Eye box 14b : Polarized sunglasses 20: Image display device 22: Reflection units 70A, 70B: Image display devices 71A, 71B: Light source unit 110: Display device 110c: Center 110p: Pixel 111: Substrate 112 LED element 112a: Semiconductor laminate 112b: Anode electrode 112c: cathode electrode 112p1: p-type semiconductor layer 112p2: active layer 112p3: n-type semiconductor layer 112s: light exit surface 112t: recess 115: wavelength conversion members 118a, 118b: wiring 120, 2120: imaging optical system 120a: bending part 120b: Direction change unit 121: Input elements 121a, 122a: Mirror surface 122: Intermediate element 122a: Mirror surface 123: Output element 123a: Mirror surfaces 130, 130e, 130f: Color change sheet 130a: First region 130b: Second region 130c: Third region 130p: Region 131: Mirror 131a: Mirror surface 140: Drive units 230, 230e, 230f, 230h, 230g: Color change sheet 230a: First region 230b: Second region 230c: Third region 230p: Region 322: Mirror 322a: Mirror surface 330: Color change sheet 330a: First area 330b: Second area 330c: Third area 330u: Minimum unit 430: Color change sheet 430a: First area 430b: Second area 430c: Third Region 530: Color change sheet 570: Reflective polarizing element 710A: Display device 710a: Light 710p: First polarized light 710s: Second polarized light 712: LED element 714: Protective layer 715: Wavelength conversion member 716A: Light scattering member 740: Reflection type polarizing element 750: reflective polarizing element 760: light shielding member 761: aperture 1000: automobile 2011: light source unit 2110: display device 2110p: pixel 2110s: light exit surface 2120: imaging optical system C: optical axis F: focal point IM1: First image IM2: Second image L: Principal ray P: Position P1: First plane P2: Second plane a1, a2: Point θ: Angle

Claims

a display device having multiple pixels and capable of displaying an image;
a color-changing sheet on which light emitted from the display device enters;
an input element into which light emitted from the color change sheet is incident; and an output element into which light that has passed through the input element is incident; the light emitted from the output element forms a first image corresponding to the image; an imaging optical system that forms
a drive unit that changes the positional relationship between the display device and the color change sheet;
Equipped with
The color change sheet is
a first region into which light enters from the pixel and emits light of a first color;
a second region into which light enters from the pixel and emits light of a second color different from the first color;
has
The drive unit sets the positional relationship between the display device and the color change sheet to a first positional relationship in which light emitted from one of the pixels enters the first area, and a first positional relationship in which light emitted from one of the pixels enters the first area. changing between a second positional relationship of incidence on the second region,
The imaging optical system has substantially telecentricity on the first image side,
A light source unit in which light emitted from the display device has a substantially Lambertian light distribution.
The color of the light emitted from the pixel is the first color,
The light source unit according to claim 1, wherein the first region transmits light incident from the pixel.
The light source unit according to claim 1 or 2, wherein the second region transmits light of the second color out of the light emitted from the pixel.
The light source unit according to claim 1 or 2, wherein the second region includes a phosphor that absorbs light emitted from the pixel and emits light of the second color.
The color change sheet further includes a third region into which light enters from the pixel and emits light of a third color different from the first color and the second color,
The drive unit determines the positional relationship between the display device and the color change sheet according to the first positional relationship, the second positional relationship, and the light emitted from the one pixel entering the third area. The light source unit according to any one of claims 1 to 4, wherein the light source unit is changed between a third positional relationship.
In the display device, the plurality of pixels are arranged along a first direction and a second direction crossing the first direction,
6. The light source unit according to claim 5, wherein in the color change sheet, the first region, the second region, and the third region are arranged along the first direction.
In the display device, the plurality of pixels are arranged along a first direction and a second direction crossing the first direction,
In the color change sheet, the first region and the second region are arranged along the first direction, and the first region and the third region are arranged along the second direction. The light source unit according to claim 5.
The light emitted from the display device has a light distribution pattern in which the luminous intensity in a direction at an angle θ with respect to the optical axis of the light emitted from the display device is approximated by cos n θ times the luminous intensity on the optical axis. ,
The light source unit according to any one of claims 1 to 7, wherein the n is a value larger than 0.
The light source unit according to claim 8, wherein the n is 11 or less.
The light source unit according to any one of claims 1 to 9, wherein the display device is an LED display having a plurality of LED elements.
The light source unit according to claim 10, wherein the light emitted from the LED element has a substantially Lambertian light distribution.
The light source unit according to claim 10 or 11, wherein the display device further includes a wavelength conversion member placed on the LED element and into which the light emitted from the LED element enters.
The imaging optical system includes a bending section including the input element, and a direction changing section including the output element,
The bending portion is configured such that a plurality of chief rays exit from different positions in the display device and cross each other to reach the first image before entering the input element, before and after the first image. bending the plurality of chief rays so that they become substantially parallel;
Any one of claims 1 to 12, wherein the direction changing unit changes the traveling direction of the plurality of chief rays so that the plurality of chief rays that have passed through the bending part head toward the formation position of the first image. 1. The light source unit according to item 1.
An opening is provided between the display device and the imaging optical system, through which a portion of light directed from the display device to the imaging optical system passes, and is directed from the display device to the imaging optical system. The light source unit according to any one of claims 1 to 13, further comprising a light shielding member that blocks another part of the light.
The light source unit according to any one of claims 1 to 14,
a reflection unit that is separated from the light source unit and reflects the light emitted from the imaging optical system;
Equipped with
The first image is an image display device formed between the light source unit and the reflection unit.
The display device is arranged on an optical path from the display device to the reflection unit, transmits the first polarized light of the light emitted from the display device, and transmits the second polarized light of the light emitted from the display device to the display device. 16. The video display device according to claim 15, further comprising a reflective polarizing element that reflects light back to .
vehicle and
The video display device according to claim 15 or 16, which is fixed to the vehicle;
A car equipped with.